The AVP (D+M anyway..) that has the lowest THD+N measured so far seems to be a Denon AVR!!

P

PENG

Audioholic Slumlord
I just bought a Purifi multichannel... but not because I understand the engineering or theory behind it.]. I left “feedback” unencrypted because I think I know at least an instance of what feedback can be—when a live mic makes a feedback tone or something of the like?
So do you have the Arcam or JBL prepro?
 
HTNut1975

HTNut1975

Enthusiast
So do you have the Arcam or JBL prepro?
I should get it on Tuesday. It was just stated on the AVS thread that a new firmware is likely going to be released next week. Good timing (I hope).
 
Gmoney

Gmoney

Audioholic Samurai
lol. Ok, I’m going to try and be as transparent as I can. Here’s how I read part of your post:

Remember "htuzr" rate is very important. Kpt jrnusgre "feedback" isn't :D Check out Bruno P's Article on "Feedback" as for "Sjgkdggjg hrggjs" [I know him! I’ve listened to him and get the general idea that he is one of the pioneer’s in current amp tech! I just bought a Purifi multichannel... but not because I understand the engineering or theory behind it.]. I left “feedback” unencrypted because I think I know at least an instance of what feedback can be—when a live mic makes a feedback tone or something of the like?
lol, really just jacking around on amp Terminology.
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
Below are the source of confusion, please just focus on the "Gain" spec, and you can see the inconsistencies in the 3 specifications.
Yeah, I saw the difference in GAIN for the previous models (RCA 34dB vs XLR 28dB) and the NEW models (RCA 28dB vs XLR 28dB).

I sent an email to ATI. This is their response:

The AT2000/3000 circuitry didn't allow us to normalize input voltage. The AT4000/6000 design allowed us to make input voltage the same for RCA and XLR, so that the same gain can be applied to both.

XLR output on most (not all) pre-amps is 6dB louder than the RCA output. But that's just a result of having two signal wires instead of one. That doubles the signal (and noise), so it's not like XLR has a better signal than the RCA, just twice as much of the same signal.

We haven't decided on output voltage for the ATP-16 or whether XLR and RCA will be the same.
 
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AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
ATI, as a reputable leading power amplifier manufacturer, please get you act together and make your specs clear!!
Since ATI normalized the Input Voltage so that both the RCA and XLR have the same GAIN of 28dB, what does this mean to our 2V-RCA = 4V-XLR discussion?

Does it still mean that 2V-RCA = 4V-XLR if the Output Voltage for the Pre-pro is the SAME for both RCA and XLR?
 
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AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
Those ATI amps are power amps. It does not change the fact that preamp/pre-pros still typically output 2 V RCA/unbalanced and 4 V XLR/balanced.
I see. For example, on the CX-A5100, it says RCA = 1V, XLR = 2V. Which means the XLR is TWICE the voltage of the RCA.

If the Pre-pro were to say "RCA = 1V, XLR = 1V", then it would mean the XLR = RCA in Voltage.

 
P

PENG

Audioholic Slumlord
I see. For example, on the CX-A5100, it says RCA = 1V, XLR = 2V. Which means the XLR is TWICE the voltage of the RCA.

:D:D

That is exactly right, it also means (obviously) that if the CX-A5100's RCA output is at 2 V, its XLR output will be 4 V, the 1:2 ratio is always maintained for any voltage, being a "linear" amplifier.

Edit: I think I should emphasize one point one more time That is, using the CX-A5100 as example, the XLR output is 2X that of the RCA output because it the amp amplifies the differential inputs of the +ve and -ve end of the input signal, vs RCA/unbalanced's "single end" signal.

So it really makes sense for power amps to lower the gain by 6 dB for the XLR inputs, in order for the amp to sound equally "loud" at the same volume position for either inputs, and to avoid degradation in THD+N due to the higher input voltage. Personally I am skeptical of what ATI has done in "normalizing" the input voltages of balanced/unbalanced, but I am sure they know what they are doing, and I don't have to like it.:D

The CX-A5100 also provided the "Maximum Output" in the manual, that's based on 0.06% THD (that's -64.437 dB)

1599856296951.png
 
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P

PENG

Audioholic Slumlord
Quite update!

This £10,000 Datasat preamp processor almost dethrone the Denon as the best measured AVP/C, it is an outdated model but the feature set seems quite current. Wonder how well the newer RS20i Dirac equipped model would measure. Who knows more about Datasat, like who actually made them?


1603977091637.png
 
VMPS-TIII

VMPS-TIII

Audioholic Chief

View attachment 41102
@PENG - If I am reading correctly how Audio Science tests these receivers it's possible these SINAD results are inflated compared to normal use?

If each test is done using pre-out mode and balanced connectors then reported performance could vary significantly from what the average user experiences using the internal amps? I don't see a measurement with this basic configuration.
 
P

PENG

Audioholic Slumlord
@PENG - If I am reading correctly how Audio Science tests these receivers it's possible these SINAD results are inflated compared to normal use?

If each test is done using pre-out mode and balanced connectors then reported performance could vary significantly from what the average user experiences using the internal amps? I don't see a measurement with this basic configuration.
Yes, measurements using balanced vs unbalanced may show some differences but will most likely be very minor, may be a couple dB. When Amir measured AV preamp/processors he typically would use balanced so tha actually puts AVRs at disadvantage because most AVRs don't have balanced pre outs. Yamaha's flag ships do, but just for the front left/right channels. ASR's measurements, like others are not going to be perfect but in general I do see apples to apples comparisons as they were done by the same person using the same Audio Precision instrument and he I believe he followed AP's suggested protocols/procedures. The problem is, as others have mentioned before, it is human nature to question how AVRs with more things jammed in one box, and relatively cheaper, could managed to measure better than preamp/processors that costs much more.
 

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